For more than a century, researchers have tried to pin down exactly why so many animal species play in their infancy. Now a new study in wild macaque monkeys has found that infants who play more actually boost key motor skills. ...

(Phys.org)—It was a pretty big week for space science as researchers at Vanderbilt University unveiled a new model of cosmic stickiness that favors a "Big Rip" demise of the universe—they have found a way to mathematically ...

The brain hidden inside the oldest known Old World monkey skull has been visualized for the first time. The creature's tiny but remarkably wrinkled brain supports the idea that brain complexity can evolve before brain size ...

Through a rare mixed-species association observed between a carnivorous predator and a potential prey, Dartmouth-led research has identified that solitary Ethiopian wolves will forage for rodents among grazing gelada monkey ...

Social grooming, or helping others to stay clean and free of lice and other ecto-parasites, has long been associated with hygiene and good health in wild primates. In the process of picking out ecto-parasites, however, the ...

Monkey

Cebidae
Aotidae
Pitheciidae
Atelidae
Cercopithecidae

A monkey is any cercopithecoid (Old World monkey) or platyrrhine (New World monkey) primate. All primates that are not prosimians (lemurs and tarsiers) or apes are monkeys. The 264 known extant monkey species represent two of the three groupings of simian primates (the third group being the 21 species of apes). Monkeys are usually smaller and/or longer-tailed than apes.

The New World monkeys are classified within the parvorder Platyrrhini, whereas the Old World monkeys (superfamily Cercopithecoidea) form part of the parvorder Catarrhini, which also includes the apes. Thus, scientifically speaking, monkeys are paraphyletic (not a single coherent group), and Old World monkeys are actually more closely related to the apes than they are to the New World monkeys.

Due to its size (up to 1 m/3 ft) the Mandrill is often thought to be an ape, but it is actually an Old World monkey. Also, a few monkey species have the word "ape" in their common name.